Enlarge ImageRequest to buy this photoHEIDI JO BRADYGillian Flynn: “I was a very shy and awkward kid — painfully shy. I always wanted to be a writer, but I wasn’t exactly booming with self-
confidence.”

With the runaway success of Gone Girl, Gillian Flynn has arrived.

Her deliciously poisonous ode to a marriage gone bad — after more than a year on best-seller lists — is heading to the big screen with Ben Affleck starring, David Fincher directing and Flynn writing.

Her previous novel, Dark Places, is also being turned into a movie, with Charlize Theron.

Flynn has written only three books.

Yet the TV critic for Entertainment Weekly who was laid off in 2008 is perched atop the literary pile.

At the recent Key West Literary Seminar in Florida, she found herself amid long-established authors who have become peers: Judy Blume, Carl Hiaasen, Laura Lippman and Sara Paretsky.

As fans lined up to talk to Flynn, someone thrust a copy of the most recent EW into her hands.

On the cover? Gone Girl, the movie.

Her movie.

“It’s insane. It really is,” she said with a smile.

“I was a very shy and awkward kid — painfully shy. I always wanted to be a writer, but I wasn’t exactly booming with self-confidence. This weekend is one of those times where I wish I could go back and say: ‘You’re going to meet Judy Blume, and you’re going to talk about her books with her; and Joyce Carol Oates. It’s going to be OK, kid; like, it’s going to be all right.’”

It has been more than all right. Gone Girl hit a sweet spot in publishing: a suspense novel with such artfully crafted twists and turns that a New York Times reviewer compared Flynn to Patricia Highsmith, the legendary writer of psychological thrillers.

Flynn’s pop-culture roots are never far from her writing — and that might be why she has been so successful. The basis for Gone Girl isn’t unique. It’s about a marriage that goes horribly, publicly wrong. But Flynn brings a fresh eye to the concept through the use of revenge, secrets and a critical look at the personas we construct for each other and ourselves. By combining reality-show culture with a universal theme of relationships, she puts her finger on something that resonates.

“There’s something to talk about for everyone: the gender roles we play; the domestic roles we play,” she said. “There’s the push and pull between husbands and wives, and how do marriages go wrong. I think people are fascinated by that. You know, people who are in good marriages fear that because they have seen good marriages go bad.”

She has not, despite reports to the contrary, completely rewritten the ending for the film, she said.

“You have to dismantle a book in order to put it back together as a movie. And it was fun to take all the different puzzle pieces and figure out what’s going to make it in the new puzzle and what can be left behind.”

Flynn is well-aware of her creepy, devious sorts of thoughts that allowed her to create a warped relationship such as the one between Nick and Amy in Gone Girl.

“I’m a big fan of setting the mood for writing,” she said. “So, for Nick and Amy, I had certain playlists put together for them. I knew kind of what would be on their iPods.”

Nick, “a child of the ’80s,” had some country and some Kiss — more mainstream than Amy, whose playlist included the Smiths.

“I discovered particularly during the writing of Gone Girl — where it’s about this toxic marriage, and you’re in Amy’s head for so long and you’re in this angry place — that it was important to kind of pull out of that.”

Her cure? Listening to songs from musicals such as Singin’ in the Rain.

Moses Supposes, a celebration of silliness, is her favorite.

“Every time I watch that, I’m like ‘And I’m happy now.’ It’s a go-to, easy fix. I could kind of — ah! — shake it off.”